Consumer and server support for extensions, including simple registration

Yadis 1.0 and OpenID 1.0 service discovery, including server fallback

Does not depend on underlying web framework

Multiple storage implementations Filesystem, SQL

Comprehensive test suite

Example code to help you get started, including
o WEBrick based consumer
o Ruby on rails based server
o OpenIDLoginGenerator for quickly creating a rails app that uses OpenID
for authentication
o ActiveRecord adapter for using an SQL store in rails